"I am grieving the loss of my boy and will not be sharing any more info on finding him."
Mcgowan said she understood it had been hugely publicised but she would never know for sure what happened.
"Things don't add up and that's all I can say," she posted.
"I lost the most sweetest genuine little soul from my life and it hurts like hell.
"I am human with a huge heart and this loss has hit me like a tonne of bricks."
Mcgowan said she wanted to thank everyone who had helped search for Hawk from the bottom of her heart.
A police spokeswoman previously told the Herald police had investigated and conducted forensic inquiries.
It appeared as though the horse was in an enclosed space and had been stolen, the spokeswoman previously said.
The death follows that of another miniature horse, Star, which had to be euthanised after being stabbed more than 40 times in a "horrific attack" in Waitati, Otago last month.
Star, a 10-year-old calf-sized horse, was found with stab wounds, including one near the jugular, in his paddock following the midnight attack in the small seaside suburb.
One of the stab wounds punctured Star's bowel and the horse died despite five hours of surgery. Police are investigating.